1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
#pragma once
// Easy window creation in C++.
//
// This header-only library uses SDL; therefore, on a Linux system, you need to
// add something to the effect of the following to your build system:
// CFLAGS += $(shell pkg-config --cflags sdl2)
// LDFLAGS += $(shell pkg-config --libs sdl2)
#include <string>
#include <vector>
#include <array>
#include <functional>
#include <stdexcept>
#include <SDL.h>
class Window {
public:
class Opts {
public:
inline Opts() = default;
inline Opts& fullscreen(bool f) { _fullscreen = f; return *this; }
inline Opts& resizable(bool r) { _resizable = r; return *this; }
inline bool fullscreen() const { return _fullscreen; }
inline bool resizable() const { return _resizable; }
private:
bool _fullscreen = false;
bool _resizable = false;
};
/// The width and height passed to this function are _suggestions_.
/// The window manager may decide to use some other size instead, and this
/// size may also change during execution (especially if resizable, but
/// perhaps also otherwise).
inline Window(const std::string &title, int wid_sugg, int hei_sugg);
inline Window(const std::string &title, int wid_sugg, int hei_sugg, Opts opts);
inline ~Window();
class Buffer {
public:
using Clr = std::array<uint8_t, 3>;
inline Buffer(int width, int height, std::vector<uint8_t> &arr);
inline std::vector<uint8_t>& raw() { return arr; }
inline int width() { return wid; }
inline int height() { return hei; }
inline void clear(Clr clr);
inline void plot(int x, int y, Clr clr, float alpha = 1.0);
inline void plotf(float x, float y, Clr clr, float alpha = 1.0);
private:
int wid, hei;
std::vector<uint8_t> &arr;
};
enum Action {
ACT_REDRAW,
ACT_STOP,
ACT_OK,
};
/// The draw buffer will be of size 3 * width * height; row-major order,
/// RGB pixels. The draw handler will be invoked if the event handler
/// returns ACT_REDRAW, but also possibly in other circumstances (e.g.
/// window resize).
using DrawHandler = std::function<void(Buffer &buffer)>;
using EventHandler = std::function<Action(const SDL_Event&)>;
inline void event_loop(EventHandler eventfunc, DrawHandler drawfunc);
private:
SDL_Window *win = nullptr;
std::vector<uint8_t> drawbuf;
SDL_Surface *surface = nullptr;
int surf_wid = -1, surf_hei = -1;
};
inline Window::Window(const std::string &title, int wid_sugg, int hei_sugg)
: Window(title, wid_sugg, hei_sugg, Opts{})
{}
inline Window::Window(const std::string &title, int wid_sugg, int hei_sugg, Opts opts) {
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
throw std::runtime_error(std::string{"SDL init error: "} + SDL_GetError());
}
Uint32 flags = 0;
if (opts.fullscreen()) flags |= SDL_WINDOW_FULLSCREEN_DESKTOP;
if (opts.resizable()) flags |= SDL_WINDOW_RESIZABLE;
win = SDL_CreateWindow(
title.data(), SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
wid_sugg, hei_sugg, flags
);
if (!win) {
throw std::runtime_error(std::string{"SDL window creation error: "} + SDL_GetError());
}
SDL_GetWindowSize(win, &surf_wid, &surf_hei);
drawbuf.resize(3 * surf_wid * surf_hei);
surface = SDL_CreateRGBSurfaceFrom(
drawbuf.data(), surf_wid, surf_hei, 24, 3 * surf_wid,
255, 255 << 8, 255 << 16, 0
);
SDL_BlitSurface(surface, nullptr, SDL_GetWindowSurface(win), nullptr);
SDL_UpdateWindowSurface(win);
}
inline Window::~Window() {
if (surface) SDL_FreeSurface(surface);
SDL_DestroyWindow(win);
SDL_Quit();
}
inline void Window::event_loop(EventHandler eventfunc, DrawHandler drawfunc) {
SDL_Event e;
while (true) {
if (SDL_WaitEvent(&e) == 0) {
throw std::runtime_error(std::string{"SDL event wait error: "} + SDL_GetError());
}
if (e.type == SDL_QUIT) break;
bool need_redraw = false;
bool need_refresh = false;
if (e.type == SDL_WINDOWEVENT) {
if (e.window.event == SDL_WINDOWEVENT_FOCUS_GAINED) {
need_refresh = true;
}
}
Action act = eventfunc(e);
switch (act) {
case ACT_STOP: return;
case ACT_REDRAW: need_redraw = true; break;
case ACT_OK: break;
default:
throw std::logic_error("Invalid Action from EventHandler");
}
int width, height;
SDL_GetWindowSize(win, &width, &height);
if (width != surf_wid || height != surf_hei) {
SDL_FreeSurface(surface);
surf_wid = width;
surf_hei = height;
drawbuf.resize(3 * surf_wid * surf_hei);
surface = SDL_CreateRGBSurfaceFrom(
drawbuf.data(), surf_wid, surf_hei, 24, 3 * surf_wid,
255, 255 << 8, 255 << 16, 0
);
need_redraw = true;
}
if (need_redraw) {
Buffer buffer{width, height, drawbuf};
drawfunc(buffer);
}
if (need_redraw || need_refresh) {
SDL_Surface *winsurf = SDL_GetWindowSurface(win);
if (SDL_MUSTLOCK(winsurf)) SDL_LockSurface(winsurf);
SDL_BlitSurface(surface, nullptr, winsurf, nullptr);
if (SDL_MUSTLOCK(winsurf)) SDL_UnlockSurface(winsurf);
SDL_UpdateWindowSurface(win);
}
}
}
inline Window::Buffer::Buffer(int width, int height, std::vector<uint8_t> &arr)
: wid{width}, hei{height}, arr{arr}
{}
inline void Window::Buffer::clear(Clr clr) {
if (clr[0] == clr[1] && clr[1] == clr[2]) {
memset(arr.data(), clr[0], 3 * wid * hei);
} else {
for (int i = 0; i < wid * hei; i++) {
for (int j = 0; j < 3; j++) {
arr[3 * i + j] = clr[j];
}
}
}
}
inline void Window::Buffer::plot(int x, int y, Clr clr, float alpha) {
for (int i = 0; i < 3; i++) {
uint8_t &orig = arr[3 * (wid * y + x) + i];
orig = alpha * clr[i] + (1 - alpha) * orig;
}
}
inline void Window::Buffer::plotf(float x, float y, Clr clr, float alpha) {
const int x0 = x, y0 = y;
const float xal = x - x0, yal = y - y0;
plot(x0 , y0 , clr, (1 - xal) * (1 - yal) * alpha);
plot(x0 + 1, y0 , clr, xal * (1 - yal) * alpha);
plot(x0 , y0 + 1, clr, (1 - xal) * yal * alpha);
plot(x0 + 1, y0 + 1, clr, xal * yal * alpha);
}
|
